924Board.org

[jseabolt]

Having owned Fiats for 20 years I know how expensive it is to service the L-jetronic system. It's a good system and mine is still working fine but I have replaced the air flow meter (>$400) and the fuel pump (leaking) so they can be quite expensive to maintain when something does go wrong.

You would think after 35 years these parts would decrease but instead it seems they keep going up! An air flow meter will cost you about as much as a new Weber carb.

Us Fiat guys have found ways to "beat the man" when it comes to Bosch parts. Like A/C Delco and Ford alternators and Weber carbs.

One time a Bosch ignition system "fix" was to subsitute a $15 GM HEI control module for the Bosch control module. I did this on my Yugo.

This 77 924 I'm looking at may have issues with the K-jetronic system. After some reading the warm up regulator may be at fault so that's $300.

Would it be worth it to convert this engine over to a Weber? Did these engines even come with a carb at one time? Wikipedia says this engine was used in the AMC Gremlins. Is that correct? I'm sure these cars used carbs.

I'm not a fan of ditching a perfectly good fuel injection system for a carburator but when push comes to shove it maybe more eccomonically to go that route if this system has issues.

Any comments?

[Khal]

[ideola]

The 2.0L block and head casting were used in several late 70s / early 80s AMC models, including the Gremlin, Spirit and one other model I can't remember at the moment. The AMC motors had a single barrel carb, so not at all what you want.

You can still get 924 carb conversion manifold adapters from European Motorworks which allow a dual DCOE or dual Dellorto setup to be installed. There are several such conversions documented here on the forum if you search.

Now for some financial perspective.

You should be aware that a complete carb conversion will be difficult to achieve for much less than $1000:
- manifold adapter => retails for ~$200
- used carbs => routinely sold on FleaBay for $400-$600
- full rebuild kit => ~$200 (need to verify, haven't checked in a while)
- new jets for carbs => $?
- fuel pump => $?
- FPR => $?
- misc fuel line & linkage bits => $? (most used carb setups will not have the proper linkage arrangement required for the 924, so you'll need to fabricate or buy something).

These are just rough guidelines, I'm sure folks have done it for less, but these numbers will give you an idea of when you're seeing a good deal on the components you'll need.

My point being, for ~$1000, you can get a rebuilt WUR + rebuilt Fuel Distributor + new Fuel pump and have $$$ left over for a new fuel filter and injector cleaning, resulting in a properly functioning CIS system that will likely last another 30 years.

New injectors for the NA are cheap. I strongly recommend buying new ones, or at a minimum sending your set to Jaguar Injector Service (or somewhere similar) and having them ultrasonically cleaned and flow matched. Send your CSV while you're at it. At $18 per injector, it's well worth it and will add minimal cost to a CIS refresh.

The fuel accumulator is the biggest bugaboo (in my opinion) because I'm not aware of a source for rebuilding, and they are expensive to buy as replacements. I know they fail, but I personally have never had one fail on the 8 or 9 running examples I've owned.

The only other component that might push you over the $1000 mark would be if you have to replace the AAV...while they do fail, they primarily affect the cold start / cold running phase, and so can be more easily ignored in the short term.
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erstwhile owner of just about every 924 variant ever made

[Khal]

Then there's this E.F.I. conversion that looks astoundingly cheap and simple...
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'80 924 Turbo

[Rasta Monsta]

[the_mad_electrician]

I get to play devil's advocate. I did a Weber conversion on my 924. I bought the peices mostly off Ebay used it cost me about $600 and I drove the car for 3 year with the Webers. I would have rather had EFI but I only paid $650 for the car and didn't want to spend what I thought was going to be $2000 just to keep it running. That EFI conversion that Khal linked was not on the board until way after I did my carbs or else I would have done it. The car did run fine with the carbs but i'd go with EFI. I guess I didn't play devil's advocate too well...
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81 924 N/A

2004 Ranger "Edge"

2005 Mazda 6

[staticsan]

The K-Jetronic system in the 924 is widely reputed to be robust and reliable. The most common expensive bit to fail is the WUR, but rebuilt ones are not hard to find and are considerably cheaper. Other things that die are much cheaper: injectors and air boots, mostly, plus the usual car things (spark plugs and filters).

It is possible to be misled with faults. My WUR needed replacing, but I did only after doing all the cheaper things (there were definitely vacuum leaks) and some careful reading.

Wade.

[Tas931]

Geeze careful you probably shouldn't use that word around here....

I think it really depends on what situation you're in. Do you know how to tune them up yourself? can you get the parts cheap? do you have other people with knowledge to help you? Do you like them in general?

For me i could pick up the bits very cheap from friends that can also help me tune it right.

if you do not have the resources available then it may be best to go to EFI as you will get loads of good help from this board.

cheers

[Cedric]

If you just want to drive get a working WUR there and and enjoy a great car. On my 931 I mounted a great working WUR and ever since its just as good as a modern car (except emissions compared to a modern car of course:)). Idles rock steady at all temperatures, starts at all temperatures and goes great. AFR:s are also rock steady during full load. So it might not be so hard to get your system working perfectly, but the US cars do have a lot of more things under the bonnet..
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1980 924 Turbo
www.instagram.com/garagecedric/

[jseabolt]

[Cedric]

Hmm, Yes the ECU is only there if you have a O2 sensor. I wonder how hard it is to convert it to eurospec Withouth all the fuzz
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1980 924 Turbo
www.instagram.com/garagecedric/

[Rasta Monsta]

No reason to dtich lambda. . .helps pass idle emissions, and off idle, it does nothing.

CIS is on millions of cars. . .this is because it is more efficient than a carb.
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Toofah King Bad

• WeiBe (1987 924S 2.5t) - 931 S3

[ideola]

The box to which you refer is not really an ECU, it is the Lambda control box.

The closest thing to an ECU on these cars is the DITC (Digital Ignition & Timing Control) found on the 1981-onward 931, but even that is a stretch to call an ECU, because it only controls ignition timing, nothing else.
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erstwhile owner of just about every 924 variant ever made

[Cedric]

Rasta, true, it's best just not to fiddle with the system. Just make it work like it's supposed to and you will be happy. I have now tested my 931 in -14°C, after 4 months in cold storage, runs perfect, the toyo t1r sucks inn the snow though:-)
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1980 924 Turbo
www.instagram.com/garagecedric/

[dreamgts]

I have a webbered 924 which goes well and hasnt given any problems at all till now. I love the webber sound especially when accelerating, if set well they can be a good replacment, and I wouldnt say they are a cheap replacement either. Ialso have a spare DITC which I would like to fit to the car which has a normal ignition system, anyone knows how to go around this or is it or is it a pros job? I guess fitting carbs all depends on what you want your car to be...

dreamgts
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2 PORSCHE 924 (CURRENT PROJECTS)
2 CLASSIC CORTINAS (FINISHED)
1 CLASSIC FIAT(FINISHED)
1 CLASSIC FIAT 132 2000CC(JUST PURCHASED)
4 SUV'S
2 SEDANS
1 OPEL PANEL VAN
WIFES SUZUKI ALTO